Note: this article is also available at my blog.

Optimizing Images for Search Engines

There's been considerable talk recently about the idea of improving the ranking of images for specific keywords. This is due to the fact that images are now appearing not just on image searches, but on the main results pages of many of the major search engines. Ask's new interface loads images in the right pane of the results, and sometimes at the top of the main results. Yahoo will sometimes, depending on the query, display the top results of an image search above the organic listings for pages. Google will often do the same, and as more of its results are coming up in what it calls "universal search," we're going to see an expansion of this, with videos, maps, links to scanned books and other different media appearing in the SERPs.

Making Use of Images and Other Media

Let's look at some of the advice people in the industry have been giving out recently. Jim Hedger of Markland Media wrote the following in an article published at the ISEDB on June 25:

There are a number of ways SEOs can use multimedia content to create a greater number of placement opportunities for unique pages in a website. The addition of video, audio, mapping (local) or even image content opens a dozen new doors in Google Universal search and Ask.com. The trick is in cross-linking with social media and local search sites and using well planned tags and titles for those files.

If, for instance, Google visits a bed-and-breakfast site and sees a well produced video promoting the region drawn from YouTube that has the faintest hint of popularity with other YouTube users, that video stands a better than even chance of finding its way into some interested party's Universal search results. Another universal winner is maps. By embedding a Google on the Contact page of a site, an SEO creates another placement opportunity in Universal results.

The next time you're updating templates for your website, think about other types of files that can be added to enhance the types of results Google might present for any given page. Make your own Placement Opportunities.

Important Traits for Image Optimization

At the Chicago Search Engine Strategies conference held in December of last year, a panel spoke on optimizing images for search engines. Grant Crowell of Grantastic Designs reported on it at Search Engine Watch. In it, he wrote that "image search is the fastest growing vertical in the search arena today. Statistics from Hitwise show it to achieve 90% growth year after year, with over 360,000,000 searches per month across the top search engines: Google, Yahoo!, Ask, MSN, and AOL."

Crowell's report goes on to list some tips for optimizing images:

Lisa Barone at the Bruce Clay blog had some similar advice earlier this week:

  • Use A Descriptive Filename: If it's a photo of Tom Brady use [Tom Brady] in the filename. IMG 230984 doesn't do much to tell the search engines what that photo depicts.
  • Don't Robots Exclude Your Images Folder: Don't laugh; people do it all the time. Your pretty, relevant images will do you no good if you put them in a folder the search engines don't have access to. Make sure your robots.txt allows the search engine to spider your images. We'd also recommend not making the path to your images overly complicated, as http://www.yoursite/images is easier for a bot to find than http://www/yoursite/images/sportsgods/male/football/greatestfootballteamever/tombrady
  • Makes Friends With The Alt Attribute: Include a descriptive and accurate alt attribute for every image on your site that needs explaining. The alt attribute should describe what the image portrays, as well as use a keyword or two when appropriate. A good rule of thumb is to use 1 word for every 16x40 slice of an image. So, if the image is 50x100 pixels, you can use (50/16) * (100/40) = 6 words.
  • Provide a Direct Link To The Photo: Provide a direct link to the file, ideally with an optimized alt attribute and actual anchor text (and from a high PR page). It should look something like this:

<a href="imagename.jpg"><img src="imagename.jpg" alt="keyword phrase"><keyword phrase in anchor text></a>

Utilizing good anchor text and linking to the photo will help the search engines decide how important the image is. Good anchor text for that smokin' photo of Tom Brady would be [View Smokin' Tom Brady photo] not [View Photo].

We had a couple of discussions about these concepts late last year and early this year at the High Rankings forum. In the first of those threads, I wrote the following about the importance of the alt attribute of an image:

I can tell you this much: Yahoo is very interested in the alt attribute.

I was checking the rankings on one of my sites yesterday, and when I ran one of the phrases through, I noticed that two images from my site were coming up in the little top four "Image Results" preview on the SERP, so I clicked through to see the full image results. Of the top 20, my site had numbers 2, 4, 5, 7, 10, and 17. Each of the images has the two-word phrase as the first two words of the alt attribute and the only other place on the pages where any part of the phrase appears is in the title tag, where a variation on the second word appears. The keywords are also not in the links to the pages on which these images appear, although they are all over the site. One other thing, and I have no way of knowing based on this whether this makes a difference: all of these images are linked, but they're linked to copies of themselves (some of them to the exact same file, some to a larger version) outside of a page, where they obviously have no place for the keywords to appear, except in the file name, where they are not present.

The home page of the site comes up at #15 for the phrase in the normal results, by the way.

And in case you're interested, this is very different from the results at Google: the site's home page is #5 for the phrase, and on the image search, one picture from the site comes up, at #7. That image does not have the phrase in its alt attribute, but the phrase is the first two words of the page's title tag.

In the second thread, in response to a question about Google showing image results in web searches on queries that included the word "images," I wrote, "It looks to be pretty rare at Google, but Yahoo does it all the time. In fact, you'll get images in the results over there even if your query doesn't include a word like 'pictures or 'images.'"

Yahoo

Yahoo SERP for fashion model picturesHave these observed traits of Yahoo's algo changed in half a year? The keyword phrase in question was [fashion model]. If you run that search through Yahoo right now, you may see images at the top of the SERP, and you may not. If you look at the image to the left, you'll see a search I ran for [fashion model pictures] after the two-word phrase failed to give me the results described in the forum thread. Note that despite the three-word query, the text next to the Yahoo Shortcut logo and above the four thumbnails reads "Fashion Model – Image Results" rather than "Fashion Model Pictures – Image Results." Moreover, the links anchored by "Fashion Model – Image Results" and "More fashion model images" both link to an image search for [fashion model], whereas the "Images" link above the search box takes the user to an image search for [fashion model pictures].

Only one of those four images is from the site I run, but that sort of change is to be expected over the course of half a year. Clicking over to the first page of image results (with SafeSearch on), my site's pictures come up in positions 4, 8, 10, 14, and 17, so the only change is that the image that had been in the second position is gone. Again, the keyword phrase is the first two words of each of my images' alt attribute, a variation of one of the words ("modeling") appears in the title tag of each of the pages, and the footer navigation of each page contains the word "fashion" twice. The site's home page now comes up at #14 in the web search.

Looking at the top four images on the SERP, we see the following:

First Image

Second Image

Third Image

Fourth Image

Yahoo: [Fashion Model] Keywords in Pages and Images
  Pg. URL File Name Alt Pg. Title Word 1 Word 2 Meta Desc.
1 No No Yes Yes Yes Yes No
2 No No No Yes Yes Yes No
3 No No No Yes No Yes No
4 No No Yes Part No Yes Part

Clearly, the image's alt attribute isn't carrying enough weight to rank the images on its own. One of the images has no alt attribute, and the alt of another is the the file name of the image it links to (a larger version of the same picture). The top three have both words from the search in their respective pages' titles, and the fourth has a variation of one of the words. It seems that factors relating to the page are carrying more weight than those relating just to the image.

Google

I noted in January that Google web searches that returned images appeared to require words like "pictures" or "images" in the query. Clearly, that's no longer the case. But what else has changed? My site's home page is now at #10 on the web search. None of its pictures come up as one of the images in the main SERP, or even in the top 100 of an image search. The nerve of some search engines. Oddly enough, the three images that appear on the web search results page are not the top three of the image search results: #1 is the same, #2 is at #11, and #3 shows up at #6, so we'd better check the top three on both pages to look for trends.

Web Search, First Image

Second Image

Third Image

Google: [Fashion Model] Image Results from Web Search
  Pg. URL File Name Alt Pg. Title Word 1 Word 2 Meta Desc.
1 No No No Part Yes Yes Part
2 Part No Yes Part Yes Yes Part
3 No No Yes Yes No Yes Yes

Image Search, First Image

Second Image

Third Image

Google: [Fashion Model] Image Results from Image Search
  Pg. URL File Name Alt Pg. Title Word 1 Word 2 Meta Desc.
1 No No No Part Yes Yes Part
2 No No No Yes Yes Yes No
3 No No No Yes Yes Yes No

Google search result for ford edselMaybe we should try another search, like [Ford Edsel]. Once again, we get a different set of results depending on whether we run a web search or an image search. The top result on the web search doesn't come up at all in the top 100 results of the image search. #2 on the web search is #1 on the image search, and #3 on web search is #2 on image search. Let's just look at those three from the web search.

First Image

Second Image

Third Image

Google: [Ford Edsel] Image Results
  Pg. URL File Name Alt Pg. Title Word 1 Word 2 Meta Desc.
1 No No Yes Yes Yes Yes Yes
2 No No Yes No Yes Yes No
3 No No No Part Yes Yes Part

What does this leave us with? At least for the time being, while the search engines work out the kinks in the software they're going to be using to determine that a given file is a picture of a face rather than a toaster, it appears that an image's relevance to a given search query is very much dependent on the page that contains the image. The name of the file doesn't appear to make a difference, and its alt attribute needn't even be present, much less relevant. It looks like the presence of the keywords on the page (perhaps in close proximity to the image) and in the title element — two of the more important aspects in getting the page itself to rank for the keywords — is what it takes for an image on that page to rank for the same keywords.